29.1 Quantization of energy  (Page 3/7)

The visible spectrum of sunlight shows a range of colors from red to violet. This spectrum has numerous dark lines spread throughout it. Noting that the surface of the Sun is much cooler than the interior, so that the surface is comparable to a cool gas through which light passes, which of the following statements correctly explains the dark lines?

1. The cooler, denser surface material scatters certain wavelengths of light, forming dark lines.
2. The atoms at the surface absorb certain wavelengths of light, causing the dark lines at those wavelengths.
3. The atoms in the Sun’s interior emit light of specific wavelength, so that parts of the spectrum are dark.
4. The atoms at the surface are excited by the high interior temperatures, so that the dark lines are merely wavelengths at which those atoms don’t emit energy.

A log in a fireplace burns for nearly an hour, at which point it consists mostly of small, hot embers. These embers glow a bright orange and whitish-yellow color. Describe the characteristics of the energy of this system, both in terms of energy transfer and the quantum behavior of blackbodies.

Give an example of a physical entity that is quantized. State specifically what the entity is and what the limits are on its values.

Give an example of a physical entity that is not quantized, in that it is continuous and may have a continuous range of values.

What aspect of the blackbody spectrum forced Planck to propose quantization of energy levels in its atoms and molecules?

If Planck’s constant were large, say ${\text{10}}^{\text{34}}$ times greater than it is, we would observe macroscopic entities to be quantized. Describe the motions of a child’s swing under such circumstances.

Why don’t we notice quantization in everyday events?

A LiBr molecule oscillates with a frequency of $1\text{.}7\times {\text{10}}^{\text{13}}\text{Hz.}$ (a) What is the difference in energy in eV between allowed oscillator states? (b) What is the approximate value of $n$ for a state having an energy of 1.0 eV?

The difference in energy between allowed oscillator states in HBr molecules is 0.330 eV. What is the oscillation frequency of this molecule?

A physicist is watching a 15-kg orangutan at a zoo swing lazily in a tire at the end of a rope. He (the physicist) notices that each oscillation takes 3.00 s and hypothesizes that the energy is quantized. (a) What is the difference in energy in joules between allowed oscillator states? (b) What is the value of $n$ for a state where the energy is 5.00 J? (c) Can the quantization be observed?